An electric motor may be used to drive an output shaft or member, such as one or more cutting blades of a mower or another implement. The speed of the cutting blades (e.g., reel mower cutting blade) may vary with the load presented by variations in ground elevation, vegetation density, vegetation moisture content, or otherwise. In addition, the speed of the cutting blades may fluctuate based on variation in the system voltage of equipment, because of other electrical loads associated with the equipment, electrical energy storage system health (e.g., battery health or state of charge), or otherwise. The fluctuation in the speed of the cutting blades may detract from finish and uniformity of the cut or mowed vegetation, for instance. Thus, there is a need to maintain a constant speed of the cutting blade to improve cutting or mower performance.